package com.fernandomdo.ServiceAdministrator;

import android.content.AsyncTaskLoader;
import android.content.Context;

/*
 * Copyright (C) 2011 Alexander Blom
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Loader which extends AsyncTaskLoaders and handles caveats
 * as pointed out in {@link http://code.google.com/p/android/issues/detail?id=14944}.
 * 
 * Based on CursorLoader.java in the Fragment compatibility package
 * 
 * @author Alexander Blom (me@alexanderblom.se)
 *
 * @param <D> data type
 */
public abstract class AsyncLoader<D> extends AsyncTaskLoader<D> {
        private D data;
 
        public AsyncLoader(Context context) {
                super(context);
        }

        @Override
        public void deliverResult(D data) {
                if (isReset()) {
                        // An async query came in while the loader is stopped
                        return;
                }
                
                this.data = data;

                super.deliverResult(data);
        }
        

        @Override
        protected void onStartLoading() {
                if (data != null) {
                        deliverResult(data);
                }
                
                if (takeContentChanged() || data == null) {
                        forceLoad();
                }
        }

        @Override
        protected void onStopLoading() {
                 // Attempt to cancel the current load task if possible.
                cancelLoad();
        }

        @Override
        protected void onReset() {
               super.onReset();
                
                // Ensure the loader is stopped
	        onStopLoading();
	        
	        data = null;
        }


}
